The present invention relates to a clinical apparatus for noninvasive investigation of sounds genera led in the human head (for example, in objective tinnitus) and in particular to a system for providing improved isolation and localization of such intracranial sounds.
Tinnitus is a perception of noise in the ears, such as ringing or pulsing that has no external source. The most common type of tinnitus is subjective tinnitus in which the patient hears sounds that is neural in origin and can only be heard by the patient. Subjective tinnitus can be the result of nerve or hair eel) damage in the inner ear or the central nervous system.
Objective tinnitus is a result of an acoustic sound source in the head or propagated from other parts of the body that, in theory, could be audible to an external observer. Subjective tinnitus can not be conventionally imaged, and even with advanced techniques subtypes are not quantifiable: likewise, objective tinnitus has many subtypes though there is no standardized method to quantify and categorize subtypes. Although objective tinnitus accounts for less than five percent of overall tinnitus cases, it can reflect a broad array of medical conditions. Some are life threatening and others can be confused with subjective tinnitus or be source of psychological distress. In cases where objective tinnitus is a result of vascular or neuromuscular disorders, such confusion can prevent a timely evaluation of these disorders, while in cases of more benign mechanisms, the inability to quantify the symptom can result in ongoing behavioral distress.